Previously, there is known a gas sensor which is provided in an exhaust pipe or the like of an internal combustion engine of an automobile for detecting a specific gas concentration in an exhaust gas as a measurement gas. As the gas sensor, there is the one that includes a sensor element which detects a specific gas concentration in a measurement gas, a housing holding the sensor element inserted thereinto, and an element cover disposed at the distal end side of the housing, for example.
For example, patent literature 1 discloses a gas sensor provided with a double-structured element cover which includes an inner cover covering the distal end portion of a sensor element provided with a gas introduction part for preventing the sensor element from being flooded, and an outer cover disposed outside the inner cover. The outer cover of this gas sensor is provided with outer introduction openings for introducing the measurement gas into the outer cover. Also, the inner cover is provided with inner introduction openings for introducing the measurement gas into the inner cover, and a louver part which is folded from the end at the axial distal side of each inner introduction opening to the inside of the inner cover and is formed toward the axial proximal end side.